Update cipher.h
Fixed typo.
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index a131452..3ee2ab7 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -82,7 +82,7 @@
MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
- MBEDTLS_CIPHER_ID_3DES, /**< The Trile DES cipher. */
+ MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */